She had the ability to command leopards, and was using them to slaughter leopard hunters when she first encountered the Black Panther. The Panther and W'Kabi had come to investigate the killings, and Madam Slay captured the Panther. The Panther escaped and fought her, until W'Kabi was able to knock her unconscious.

After Killmonger's first death, Madam Slay preserved his body with secret herbs. She kept watch over the body until one night when the Mandarin came to take it away. Using his rings, the Mandarin was able to amplify the Resurrection Altar and restore him to life. Killmonger returned to Madam Slay and the two plotted to kill the Black Panther and return Wakanda to its ancient ways.

While Tony Stark visited Wakanda, Madam Slay drugged Jim Rhodes and took him prisoner. Killmonger appeared to have killed the Black Panther, and blamed Rhodes and Stark, convincing the Wakandans that he could lead them to vengeance. The Black Panther returned, revealing that he had faked his death using an LMD. The heroes attacked, and Madam Slay called in Killmonger's troops, but the Black Panther still defeated Killmonger. The Mandarin recalled his ring, and Killmonger reverted to an inanimate skeleton.